String instrument



y 15, 1940- M. RWEFEA STRING INSTRUMENT Filed July 27, 1959 PatentedJuly 16, 1940 UNITED STATES PATENT OFFICE STRING INSTRUMENT ApplicationJuly 2'7, 1939, Serial No. 236,741

4 Claims.

This invention relates to improvements in string instruments, andparticularly to the bridge construction for the tops or sound boards ofthe instruments. It is specifically described in con- '5.. neotion witha guitar although it should be understood that the invention is not tobe considered limited to instruments the strings of which have to beplucked. v

It is an object of the invention to attain greater beauty and fullnessof tone by inducing vibration of the sound board in a different andamplified degree compared with that vibration which is induced inguitars of the known construction.

The invention also has the object of providing a guitar in which thenumber of frets is increased over the number of frets (usually 12 frets)with which the standard guitar is equipped, thereby increasing theplaying range of the instrument.

The invention also has the object of providing an instrument havinggreater resonance than the instruments heretofore known and in generaluse.

With these and numerous other objects in view, an embodiment of theinvention is described by way of example in the following specificationin which reference is made to the accompanying drawing. 7

In the drawing:

Fig. 1 is a front elevation of the improved guitar:

Fig. 2 is a side elevation of the same.

The guitar has the usual body with a bottom I, the side 2, and the top3, which latter constitutes the sound board of the instrument. The bodyof the instrument slightly higher at the lower end than at the upper endis supplemented by a neck 4 directly secured thereto and provided withthe usual keys 5 through which the strings 6 may be adjustably tensionedas required.

The strings 6 (of which six are shown as in the standard guitar) extendfrom these tensioning keys or pegs over the frets l on the neck and overa sound hole Sin the top or sound board 3 of the body. They are securedat their ends to a bridge 9 which is firmly located on top of the soundboard; as for instance, it is advisably fixed in position by glue or insome other suitable way.

The bridge 9 in the present invention is shown as being disposed at thatpoint of the sound board or top 3, at which the vibrations have theirmaximum amplitude.

The body of the instrument itself may be reinforced in the usual way.For this purpose, ribs Ill fastened to the under face of the sound boardextend radially, so that their prolongation would intersect the medialplane of the board at a point on the edge of the sound board. These ribsshown in dotted lines, however, do not extend over the full length ofthe board, but terminate adjacent a transverse rib l I which also issecured to the lower face of the board 3 slightly spaced from the soundhole ii. A further reinforcement rib H extending transversely on theunder face of the board also arranged at the opposite side of the soundhole 8 and at approximately the same distance from it as rib l I.

The bottom of the body also may be provided with transverse reinforcingribs, and the side or circumferential wall of the body may have posts,not shown. This circumferential wall may be united with the top and thebottom respectively 10 by strips (not shown) along the inner face of thewall 2 at its top and bottom edge, and glued to the instrument.

, The above construction furnishes a sound board, as it is usuallyemployed in guitars of the 15 Spanish type. Owing to the provision ofthe transverse rib ii, the part of the sound board secured to this ribforms a nodal point for the vibrations of the board, the vibrationshaving the maximum amplitude at a point which is approxi- 20 matelycentrally of the area of the board confined by the rib l I and thecircumferential edge, namelythe area beneath which the radial ribs itare applied.

But while the construction here shown illus 5 trates the Spanish type ofguitar, the invention is equally applicable to the so-called Americantype guitars.

It is at the point of maximum amplitude of vibrations hereinafter calledthe focus of vibra- 30 tions at which the bridge Q is located.

In the Spanish guitar, as known in the prior art, the lower ends of thestrings are secured to a bridge which is directly glued to the top ofthe body. In the American type guitar which is dis- 35 tinguished fromthe Spanish guitar by different bracing, the lower ends of the stringsalso may be secured to a bridge as in the Spanish guitar, or they aresecured to an anchor piece which in its turnis fastened to thecircumferential wall of the 40 body, preferably at a. point inopposition to that circumferential point of the body from which the neckof the instrument extends. The lower anchoring elementin Americanguitarstherefore, corresponds to that anchoring element which is in 5general use on violins and other string instruments to be played withthe bow.

The present invention is distinguished from the manner of attaching thestrings, as known in either type of guitar, by the fact that the lowerends only of the strings 6 are secured to a bridge 9 fastened to the top3 of the body at the focus of vibrations; the strings intermediate thisanchoring bridge 9 and the pegs 5 are tensioned and syntonized over anauxiliary bridge I2 which is located between the main anchoring bridge 6and the sound hole 8.

The Spanish guitar usually is provided with twelve frets on the neckbetween the head and body. Owing to the selection of an auxiliary 5Obridge 12 spaced from the focus of vibrations the guitar may be builtwith fourteen frets or more on the neck, while still retaining thelocation of the main bridge in the usual position. By providinganadditional bridge l2, closer to the syntonization knob [5 on the head,it will now also be feasible to increase the number of frets on thefingerboard l6 extending the additional frets downward over the body ofthe instrument and the neck extension. The number of frets, forinstance, may be increased to fifteen, sixteen, or even seventeen. Thelength of neck on which these additional frets are provided is inpredetermined relation to the distance between the auxiliary bridge [2from the main bridge 9. Proper spacing of the auxiliary bridge I2 fromthe main bridge will lead to complete syntonization of the notes of thescale.

The anchoring bridge 9 is shown to be provided with a raised extensionI4 wherein,-in the embodiment illustrated, the ends of the strings 6 aretied by knots. It is obvious, however, that anchorage by pegs or thelike as it is known from the standard practice, may be provided.

The Spanish guitar usually is provided with twelve frets on the neckbetween the head and body. By positioning the additional bridge l2closer to the syntonizing knob E5 on the head, the number of frets onthe neck of the same length may be increased. Owing to this reduction ofthe space occupied by the individual frets, the fingerboard l6 formingthe extension of the neck above the upper portion of the sound boardwill then be also adapted to receive a greater number of frets ofprogressively reduced width. In this manner the playing range of theguitar may be increased from approximately an octave and a half to twooctaves since as many as twenty-four frets can be positioned on the samelength of neck and fingerboard which up to now received as a ruleeighteen or nineteen frets.

The player, therefore, may play on these frets from the twelfth to thefifteenth over the neck of the guitar away from the top thereof, and

higher frets may be within the shortest reach so thatin spite of theincrease of the playing range to two octaves, the performance on theinstrument is greatly facilitated.

In the playing of the instrument, it has, however, been discovered thatowing to the application of the pull on the sound board in the focus ofvibrations, as in the standard guitar, and the application of thetensioning and syntonizing element at a distance from said focus ofvibration, the fullness of the sound, the beauty of the tone and theresponsiveness of the instrument are greatly enhanced. The provision ofthe auxiliary bridge at a distance from the focus of vibrations is ofextremely beneficial eifect on the instrument.

The auxiliary bridge may adjustably rest on the top of the sound board3, for which purpose it may be provided with a plurality of short baseportions or feed. Like other bridges on string instruments, it tapers incross-section from the narrow tip towards the wider base to facilitatesyntonization of the instrument. While the aux iliary bridge l2 also maybe glued to the sound board 3 of the instrument like the main bridge 9,it is obvious that this auxiliary bridge is adapted to be held in itsoperative position solely by the pressure of the strings placed thereon.

I am aware of the fact that it has been proposed to secure the stringsof the instrument by pegs to the top of the body, and to provide a topwould not be interfered with in any way by the hands when playing. Itwas also believed that in this manner the vibration of the strings wouldbe directly transmitted to the sound board without dissipating anyenergy of vibration through contact with the body. In the presentarrangement, the strings are anchored at their ends of the sound board,but are additionally tensoned over a bridge fixedly located, though itmay be adjustable, on the sound board itself, exerting thereby a doubleinfluence upon the sound board and modifying the vibrations of thelatter to great advantage.

I claim:

1. In an instrument of the character described, the combination of abody having a sound board, a neck, a bridge secured to the sound boardsubstantially centrally of the area of vibrations, strings secured attheir endsto the bridge and neck respectively, and an additional bridgespaced from the first bridge and resting on the same sound board, bothof said bridges being supported on the vibratory sound board exclusivelyand being adapted to vibrate with the sound board.

2. In an instrument of the character described, the combination of abody having a top, a neck extending from said body and one end thereof,a bridge secured to the top only, strings each attached at one end tothe bridge, the other end of each string being adjustably fastened atthe neck, and an auxiliary bridge, resting on the top only between thefirst named bridge and that end of the top from which the neck extends,the strings being tensioned inengagement with the auxiliary bridge,whereby vibrations of the strings are converted into vibrations of thetop through both bridges the first named bridge being positionedsubstantially at that point of the board at which the vibrations havethe maximum amplitude the strings being secured at one end to a pointwhich does not vibrate with the sound board while the strings at theother end are secured to the bridge which vibrates with the sound board.

3. In an instrument of the character described, the combination of abody, a sound board on said body, a neck, a bridge secured to said body,strings fastened to the bridge and to the neck, the bridgebeing locatedin the focus of vibrations produced upon plucking the strings, and asecond bridge over which the strings are tensioned and located closer tothe neck than the first named bridge.

4. A musical instrument of the string type, comprising a body, a soundboard on top of the body, the marginal portions of the sound board beingheld against vibration by connection of said marginal board at itsmargins with the body, the remaining portion of the sound board beingfree to vibrate, a neck extending from said body, a bridge mounted onthe sound board in a position to vibrate with the same, strings anchoredat one end to the non-vibratory neck and at the other end to thevibratory bridge on the sound board, and a second bridgeinterposedbetween said first named bridge and the neck over which the strings aretensioned.

MODESTO RIVERA.

